The closest I ever got to cars being parked within the confines of a stadium was the back straight at Dudley Wood. Recall talking to Hans Nielsen's wife, Suzanne, who was watching the racing from his van.
Apparently Billy Connolly used to joke (before he was struck down with his illlness) that he only needed one book on his shelf because after reading it he would forget what he had just read and would read it again!